About oracle path for configure file

first,
tnsping dev02, test configure in tnsnames.ora file,it's ok
secod
sqlplus username/password@dev02, is also work

but when i start the program, it return an exception
"Server did not respond within the specified timeout interval"

after contrast above two case,

i thinck it may be the configure has some problem, so i copy another program configure file to the machine, so i update the configure file.such as
before:
    <add key="Set.NLS_LANG" value="GERMAN_GERMANY.WE8MSWIN1252"/>
    <add key="Set.PATH.x32" value="%HOME%\Oracle.x32;%PATH%"/>
    <add key="Set.PATH.x64" value="%HOME%\Oracle.x64;%PATH%"/>
    <add key="Set.TNS_ADMIN" value="%HOME%"/>
after:
    <add key="Set.NLS_LANG" value="GERMAN_GERMANY.WE8MSWIN1252"/>
    <add key="Set.PATH" value="%HOME%;%PATH%"/>
    <add key="Set.TNS_ADMIN" value="%HOME%"/>
Then it works. but i not very clear why it happen ? may be by the driver